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A268336 a(n) = A174824(n)/n, where A174824(n) = lcm(A002322(n), n) and A002322(n) is the Carmichael lambda function (also known as the reduced totient function or the universal exponent of n). 7
1, 1, 2, 1, 4, 1, 6, 1, 2, 2, 10, 1, 12, 3, 4, 1, 16, 1, 18, 1, 2, 5, 22, 1, 4, 6, 2, 3, 28, 2, 30, 1, 10, 8, 12, 1, 36, 9, 4, 1, 40, 1, 42, 5, 4, 11, 46, 1, 6, 2, 16, 3, 52, 1, 4, 3, 6, 14, 58, 1, 60, 15, 2, 1, 12, 5, 66, 4, 22, 6, 70, 1, 72, 18, 4, 9, 30, 2, 78, 1, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..81.

FORMULA

a(n) = A174824(n)/n.

a(A124240(n)) = 1. - Michel Marcus, Feb 21 2016

MATHEMATICA

Table[LCM[n, CarmichaelLambda@ n]/n, {n, 100}] (* Michael De Vlieger, Feb 03 2016, after T. D. Noe at A174824 *)

PROG

(MAGMA) [1] cat [Lcm(n, CarmichaelLambda(n))/n: n in [2..100]]: // Feb 03 2016

(PARI) a(n)=my(ps); ps=factor(n)[, 1]~; m = n; for(k=1, #ps, m=lcm(m, ps[k]-1)); m/n \\ Michel Marcus, Feb 21 2016

(PARI) apply( {A268336(n)=lcm(lcm([p-1|p<-factor(n)[, 1]]), n)/n}, [1..99]) \\ [...] = znstar(n)[2], but 3x faster. - M. F. Hasler, Nov 13 2019

CROSSREFS

Cf. A002322, A068563, A124240, A174824.

Sequence in context: A187730 A049559 A063994 * A295127 A076512 A128707

Adjacent sequences:  A268333 A268334 A268335 * A268337 A268338 A268339

KEYWORD

nonn,easy

AUTHOR

Juri-Stepan Gerasimov, Feb 01 2016

EXTENSIONS

More terms from Vincenzo Librandi, Feb 03 2016

STATUS

approved

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Last modified April 22 12:53 EDT 2021. Contains 343177 sequences. (Running on oeis4.)